This invention relates to a slidable closure for slide closure of metallic vessels.
Closure elements of this type are for example known from German Allowed Application No. 2,620,423. In this construction the closure element is a plate of heat resistant material which is provided with an opening through which molten metal can pass out of the metallurgical vessel. The plate is inserted into a frame of approximately C-shaped configuration and thereafter the open side of the C is closed by placing a retaining member across it and connecting the retaining member to the frame by means of screws. The plate is guided in the frame by having its longitudinal edges bevelled and by having the frame itself provided with correspondingly configurated grooves in its longitudinal sides.
A problem with this prior art is that the manufacture of the frame is relatively expensive because it is complicated. Bevelling of the longitudinal edges of the plate themselves also requires additional operating steps and, moreover, brings with it the danger that when the plates are inserted or removed from the frame the edges may break. It is to be understood that because of the particular configuration of the known frame, it is not possible to insert or remove the plate in the plane of the frame. Rather, after the retaining member is removed from the frame the plate must first be shifted relative to the frame in the plane of the frame until the bevel longitudinal edge of the plate moves out of engagement with the corresponding groove of the frame. Thereafter, the plate must be lifted up at the opposite edge and must be removed from the frame in the direction normal to the plane of the frame. This handling during mounting or dismounting of the plate is relatively complicated and runs a considerable risk of danger to the plate which is already of rather brittle material.